My understanding is that any front-end analytics solution will require consent. You're right about explicitly set preferences. I was mixing that up with inferred preferences.
How many requests per second are being served? How many error codes were delivered to clients? How quickly the service responded? Service logs without PII? All perfectly fine to aggregate and analyze without consent.
Acting dense like this isn't productive... And literally this information would be stores as anonymous user 12345, but that still would require consent (probably, or at least arguably).
Stats like that are only used to implement dark patterns better and justify user hostile decisions since pretty much the time the idea of telemetry was introduced. Otherwise, we'd live in the world of perfect web ui and we're not.
Is it a violation to send data that could theoretically be used for more invasive tracking than you actually do? I don't think so, or else you'd need consent just to receive an IP packet.